Helical building



March 7, 1967 R. F. WITTENMYER ET AL 3,307,307

HELICAL BUILDING iiiiiiiiii INVENTORS' w RICHARD E WITTENMYER BY HARRYHODSON V 7 I W W f A TQRNEYS HELICAL BUILDING 49 FIG. 3

44 RICHARD F. WITTENMYER FIG.4 BY HARRY HODSON TORNEYS,

3 Sheets-Sheet 5 INVENTORS RICHARD E WITTENMYER R. F. WITTENMYER ET LMarch 7, 1967 HELICAL BUILDING Filed March 2. 1964 United States Patent3,307,307 HELICAL BUILDING Richard F. Wittenmyer and Harry Hodson,Cleveland, Ohio, assignors to The Austin Company, a corporation of OhioFiled Mar. 2, 1964, Ser. No. 348,506 8 Claims. (Cl. 52-17s Thisinvention relates to parking garages and, more particularly, to animproved vehicle parking garage.

Priorly, numerous attempts have been made to provide multi-story parkinggarages with ramps between floors and with provision for parking on thevarious floors. These garages, however, exhibit numerous disadvantages.For example, they employ a large amount of floor space to provide thenecessary ramps, which ramps limit available parking area. Also, becauseof the complex network of roadways and the difliculty of maneuveringvehicles through these roadways, these structures require attendants topark and retrieve the cars. Still other disadvantages of these knowntypes of garages are the short turns and intersections which definetraffic hazards when vehicles are coming from dilferent directions toenter a common ramp. Further, although attempts have been made toprovide all-ramp type garages, these attempts have resulted inuneconomical structures having separate entrances and exits for each oftwo-ramp type structures with no provision for driving from onestructure to another. Thus, these structures prevent maximum utilizationof the parking area.

Accordingly, it is an object of this invention to provide a garage whichobviates the above-mentioned disadvanta es.

It is another object of this invention to provide an improved all-ramptype garage which makes maximum utilization of the garage structure toprovide a maximum amount of parking area.

Still another object of this invention is to provide an improved parkinggarage in which the driveways are uniform, free form sharp turns,hazardous intersections and oncoming traffic so that the customers maypark and retrieve their own vehicles without creating trafiic hazards.

It is a further object of this invention to provide an improved parkinggarage which can be quickly, easily and economically constructed.

It is a still further object of this invention to provide an improved,all-ramp type parking garage which provides a maximum ratio of parkingarea to driveway area and which provides for easy ingress and egress ofthe vehicles and predestrians without introducing traffic problems.

Another object of this invention is to provide an improved parkinggarage in which a large number of identical pre-cast, pre-stressedconcrete sections are employed which may advantageously include meansfor post-stress- It is a still further object of this invention toprovide a parking garage with a pair of spiral, all-ramp structures,each including parking areas on each side of a radially centered, singlelane driveway in which the parking stalls are angularly disposedrelative to the driveway to facilitate the entrance and exit of thevehicles from the stalls. Advantageously, this arrangement provides forthe maximum utilization of the space because it provides a maximumparking area to driveway ratio.

Yet another object of this invention is to provide an improved parkinggarage with a plurality of spiral all-ramp structures inter-connected bycrossovers, or bridges, to facilitate the ingress and egress ofvehicles.

A still further object of this invention is to provide an improvedparking garage with a plurality of helical, allramp structures withcrossovers inter-connecting corresponding levels on the respectiveramps, one of the structures spiraling in one direction and at least oneother structure spiraling in the opposite direction, entrance meansconnected to one of the helical structures and exit means connected toat least one of the other helical structures, each structure having asingle lane driveway positioned between two series of radially spacedparking stalls.

Another object of this invention is to provide in a garage a pluralityof helical, all-ramp structures, one spiraling in one direction andanother spiraling in the opposite direction with pedestrian ramp meansalong the inner edges of the helices to provide safe pedestrian paths sothat the pedestrians may quickly and safety ascend and descend thestructures.

Briefly, in acordance with aspects of this invention, at least twospiral, or helical, structures are positioned in side-by-siderelationship with either the two structures or the direction of travelthereon, but not both, being of opposite hand, one clockwise and theother counterclockwise. These structures are inter-connected atcorresponding levels so that an entranceway may be provided for only oneof the structures and an exitway provided for the other structure andthe traffic will always progress in one pattern throughout therespective structures. Advantageously, each spiral structure is providedwith a radially positioned, single lane drive intermediate the spiralstructure to provide parking areas in the form of a series of stalls oneach side of the drive.

According to other aspects of this invention, the parking stalls arepositioned at acute angles relative to the drive to permit the vehiclesto enter and leave the stalls with a minimum of turning of the steeringwheel.

In accordance with further aspects of this invehtion, a pedestrian rampis provided along the inner edge of each helix so that the pedestrianshave a safe walking area remote from the traflic.

Advantageously, the parking garage may be formed from a plurality ofidentically shaped interior and exterior edge beams and a plurality ofidentically shaped, precast, radially tapered floor units whichincorporate their own longitudinal beams so that the major portion ofthe construction of a number of buildings can be accomplished at asingle site and the assembly accomplished on the garage site with theaddition of columns which are conveniently pre-cast or cast in place.Also advantageously, these tapered floor units include cables which canbe posttensioned to provide additional support for the concrete floorunits. The pre-cast floor units may be formed with a triangular shapedouter edge to define corners for the vehicle stalls along the outerperiphery of the spiral, or helical, ramp and the inner edge of thepre-cast floor units may be provided with a segmented circularpedestrian ramp. The parking garage can be quickly and easilyconstructed by casting in place a predetermined number of reinforcedinner columns and a plurality of reinforced outer columns. These outercolumns are inter-connected with pre-formed reinforced beams whichconnect the respective outer columns to define an outer circle. A groupof identical pre-cast beams connects the respective inner columns todefine an inner circle. The radially tapered pre-cast floor units arethen placed to bridge the inner and outer beams in a continuous all-rampstructure. Bridges are then cast between corresponding levels of thestructures.

In one embodiment, at least three helical structures are constructedwith their axes parallel and with their peripheries adjacent each other,one helix for upward traffic flow and two helices for downward trafficflow, or vice versa, with bridges interconnecting the first helix witheach of the others. The upward helix or helices serve as entrance rampswhile the downward helix or helices serve as exit ramps. Each of theramps has parking space on both peripheries of a centrally located,single lane driveway, which arrangement facilitates the exit of traffic.

Other objects and a fuller understanding of the invention may be had byreferring to the following description and claims, taken in conjunctionwith the accompanying drawings, in which:

FIGURE 1 is a partial plan view of one illustrative embodiment ofparking garage according to this invention;

FIGURE 2 is a partial sectional view, in elevation, taken along thelines 22 of FIGURE 1 with the pedestrian ramp and outer railingsremoved;

FIGURE 3 is a partial view, to an enlarged scale, of the first floor ofthe sector cut out of FIGURE 1 by the lines 22;

FIGURE 4 is a view in elevation, partly in section, of the left handhelix of FIGURE 1 to the same scale as FIGURE 3;

FIGURE 5 is a plan view, partly broken away, of a double cantilever Tbeam floor unit to an enlarged scale relative to FIGURE 3;

FIGURE 6 is a sectional view of the T beam floor unit shown in FIGURE 5,taken along the line 6--6;

FIGURE 7 is a view in elevation of the T beam floor unit shown inFIGURES 5 and 6 taken along the lines 7-7 of FIGURE 5; and,

FIGURE 8 is a plan view to a greatly reduced scale of anotherillustrative embodiment of this invention.

FIGURE 1 shows a plan view, partially broken away, of one illustrativeparking garage according to this invention and FIGURE 2 is a view inelvation and in section of the left hand structure of FIGURE 1, takenalong the lines 2-2 of FIGURE 1 and including a portion of the righthand structure of FIGURE 1. FIGURE 2 does not show the pedestrian rampand the safety devices which will be subsequently shown and described.FIGURE 1 includes a first spiral, or helical, structure 10 which, inthis particular instance, spirals upwardly in a clockwise direction asindicated by arrow 11 and a second spiral, or helical, structure 12which spirals downwardly in a clockwise direction as indicated by arrow13. Stated in another manner, the structures 10, 12 spiral in oppositedirections with respect to ascending elevations. The structure areinterconnected at corresponding elevations by a plurality ofsubstantially horizontal bridges 16. The par-king garage includes asingle entrance 18 and a single exit 20. Each of the helical structures10, 1 2 includes a single lane driveway 22, 23, respectively, radiallypositioned intermediate the helix as outlined by the concentric helicallines 24., 25 and 26, 27. The structures 10, 1 2 are each provided withtwo series of parking stalls 30, 3 1 on opposite sides of the respectiveconcentric helical lines 24, 25 and 26, 27.

Each of the structures is formed by casting vertical columns in a pairof concentric circles on the garage site and these columns are cast onsuitable foundations not shown or described. For example, structure 10is formed with a plurality of interior columns .34, positioned in acircle, and a plurality of exterior columns 36, also positioned in acircle concentric with the circle defined by columns 34. After thesecolumns are formed in position, they are interconnected by beams whichare placed on cast-in-place reinforced concrete wedges, or supports, notshown, on the respective columns so that a plurality of exterior edgebeams connect the columns 36 while a plurality of substantiallyidentical interior edge beams connect the interior columns 34,, whichbeams will be subsequently shown and described. Similarly, the structure12 is formed by easting a plurality of interior columns 3 8 and aplurality of exterior columns 40, concentric with the circle defined bythe interior columns 38. The exterior columns 40 are connected withexterior edge beams and the interior color a spiral below grade.

umns 38 are connected by interior edge beams. The tops of the exteriorcolumns 40 are interconnected by a series of top edge beams 41 toimprove the esthetic appeal of the structure and to give the columnsincreased stability. Similarly, the exterior columns 36 areinterconnected by a series of top edge beams 41.

As a safety precaution, each stall may be provided with a vehicle stopmember, or bumper, 42 shown on certain of the stalls 30 of the structure.12. As a further safety measure, each structure is provided with aseries of spring tensioned vertical cables 43 which are connected aroundthe periphery of the helices and are interconnected by generallyhorizontal cables to define an outer safety railing 44. Preferably,these cables 43 are connected between the top edge beams 41 and thefoundations of the structures by means of springs, not shown, so thatthey will yield without snapping if struck by a vehicle.

Several provisions are made for the ingress and egress of pedestrians.For example, each of the structures may be provided With an elevator,such as an elevator 45 for the structure 10 and an elevator 46 for thestnucture 12, or a single elevator may be provided for both of thestructures. These elevators are connected with each of the bridges 16 bymeans of a walk 47 which is protected by a railing 4 8. A pedestrianhelical ramp 49 is also provided around the inner periphery of each ofthe structures 10,, 12, and each ramp includes an inner railing 50 andan outer railing 52. The inner railing 50 is defined by a number ofrelatively short sections spaced from the interior columns to permit theingress and egress of pedestrians between the railing sections and theinterior columns. The top fioor of each of structures 10, 12 terminatesin a radially aligned fence 51 which extends over the top bridge 16.

FIGURE 3 shows, to an enlarged scale with respect to FIGURE 1, the firstfloor of the sector cut oif by the lines 22 of FIGURE 1. This viewincludes the ground level portion 53 of the foundation which may behorizontal The pedestrians may pass from the end of ramp 49 onto theground in the direction of arrow 54. The junction between the inclinedportion of helix 12 and ground portion 53 is defined by a dotted line55. This view also shows the inclined portion 57 of the foundation whichdefines a passage to the exit 20 as indicated by arrow 58 and meets theedge of a first of a series of floor T beam-s 60. The flooring for theaboveground portion of each of the helices is provided by this series orsubstantially identical tapered, pre-cast and prestressed T beams 60,which will be subsequently described in detail.

FIGURE 4 is a view in elevation, partly in section, of the helix 12 tothe same scale as FIGURE 3. The T beams 60 have their longitudinaldimension on radii of the respective structures 16), 12 and are eachsupported by an exterior and an interior edge beam, 62, 63,respectively. The line 64 indicates the ground level from which theinclined portion 57 of the foundation defines the beginning of the helix12. A triangular portion 66 of beam 60 extends beyond exterior edge beam62 to define a cantilever portion. Although only portions of thepedestrian railings 52, 50 are shown, it is apparent that the portionsof the floor beams 60 defining pedestrian ramp 49 are, in fact, each acantilever 67 which extends beyond the interior edge beam 63. Thesecantilever portions will be described in detail with respect to FIGURES5 and 7.

FIGURE 5 shows a plan view, partly broken away, and to an enlarged scalerelative to FIGURE 3, of the double cantilever floor T beam 69 used toform all the fioor of the parking garage which is above the inclinedportion of the foundation. Each of the beams 60 is tapered andterminates in an outer triangular cantilever section 66. The end of thebeam 60 opposite from the triangular section 66 is the second cantileversection 67 which is a section of a circle defining a short length of thepedestrian spiral ramp 49. The T beam 60 has a pair of longitudinaledges 68, 69, each of which lies on radii of the respective helix whenthe beam is installed in the building. The beam 60 is preferablypre-cast concrete in which a mesh screen 76, shown to an enlarged scale,is imbedded in the floor surface as one reinforcing means and thisscreen may be of the order of two-inch meshes of No. 12 wire. FIGURE 5also shows the vertical columns 38, 40, each with a group of reinforcingrods 70', each group having an interlacing wire 71. Similar reinforcingis employed in columns 34, 36.

The T portions of T beams 60 are also provided with pre-stressing andpost-tensioning means which will be subsequently described. The secondcantilever section 67 of T beam 60 extends beyond the interior edge beam63, as viewed in FIGURES 5 and 7, and has pipe railings 50, 52 along theinner and outer edges, respectively. The inner railing 50 is in shortsections spaced from each interior column 34 or 38 to permit pedestriansto enter and leave the spiral ramp 49.

FIGURE 6 is a view in section, of the beam of FIG- URE 5, taken alongthe lines 6-6 thereof. The T beam 60 has a pair of longitudinal T-shapedreinforcing sections 74, 75, each of which has a plurality of steel rods76 of a first diameter and at least one rod 77 of a larger diameter. TheT sections 74, 75 are each provided with a pair of end plates 78 onopposite ends thereof and the rods 76 are preferably pre-stressed andsecured to these end plates 78. Advantageously, the rods 77 extendthrough the end plates 78 and are post-stressed to provide additionalreinforcing for the T beams in a manner which will be subsequentlydescribed.

In FIGURE 6 a pair of joints 80, 81 between the next adjacent, partiallyshown, T beams 60 completes the floor surface and these joints are castin place after the beams 60 are positioned on the'beams 62, 63. Thescreen 73 is held near the surface of the beam 60 at the T-shapedsections 74, 75. Between the T sections 74, 75 the screen bowsdownwardly near the lower surface of the beam and after the beam is setthis bowed portion of the screen 73 provides transverse reinforcement ofthe beams 60. v

Referring now to FIGURE 7, there is depicted a longitudinal view, inelevation, of the beam 60 taken along the lines 77 of FIGURE 5. -Astherein shown, the longitudinal T sections 74, 75 fit between theinterior and exterior beams 62, 63 and the rods 77 extend throughsuitable notches, not shown, in the edge beams. A plate 85 is attachedto the outer end of the rod 77 and on the outer surface of beam 62 bymeans of a nut 86. Another plate 85 is connected to the inner end of therod 77 and on the inner surface of beam 63 by means of another nut 86and the nuts 86 are tightened to provideposttensioning of the beam 60.

The edge beams 62, 63 are preferably L-shaped in cross-section as shownin FIGURE 7. Interior L-shaped edge beam 63 has a lower portion 88 whichprojects to the left and engages the interior ends of the T sections 74,75. Similarly, on the opposite ends of the beam 60, the exterior edgebeam 62 has an L-shaped cross-section including a lower portion 89 whichprojects inwardly and engages the ends of T sections 74, 75.

When the beams 60 are being cast a plurality of eye bolts 90 arepositioned to project from the edges of the triangular section 66 toreceive the vertical cables 43. In cutting the screen 73 before it isplaced in theconcrete, it is measured and cut to provide an overlap oneach side of the beam which is preferably equal to the width of thefloor joints 80, 81 to thus provide reinforcement for these joints.

FIGURE 8 shows a plan view to a greatly reduced scale relative to FIGURE1, of another embodiment of this invention. In this embodiment a firsthelical structure 92 is a structure similar to the structure 10 of FIG-URE 1 in that it is provided with an entrance 93 and spirals upwardly ina clockwise direction as indicated by an arrow 94. A pair of structures95, 96, each corresponding with the construction of helix 12 of FIGURE1, is also provided. These structures each have an exit ramp 97, 98,respectively, and are each connected to the helix 92 at correspondinglevels by means of one of a pair of bridges 100, 102. This arrangementgreatly facilitates the egress of the vehicles, especially where aparking garage has a utilization pattern of gradually filling in themorning but quickly emptying in the evening rush hour.

In use, the helical structures 10 and 12 have decided advantages as aparking garage. A person will drive his automobile in the entrance 18and will spiral clockwise upwardly until he finds an empty parking stallin which he will park his automobile. If an empty stall cannot be foundin the first complete revolution, he may continue on up for as manyrevolutions as necessary to reach an empty stall. The fact that the twohelical structures 10 and 12 are open on the sides and with the viewobstructed only by the vertical cables 43, permits the driver of thevehicle to easily look over to the other helical structure 12 to see ifthere are vacant parking stalls in that structure. If there are, he maycross over at any one of the connecting bridges 16 and start a downwardspiral in a clockwise direction to-reach such unoccupied parking stall.Upon parking his vehicle, the driver may then walk up or down the spiralpedestrian ramp 49 to reach the exit or to reach one of the elevators45, 46. Since these spir-al pedestrian ramps 49 are on the inside of thehelix, they are in a safe position for the pedestrians and also providea short path for the pedestrians.

The fact that the driveways 22 and 23 are single lane provides safety inthat a driver will not be surprised by a vehicle coming in the oppositedirection. Further, since the parking stalls are at an angle rather thanperpendicular to the driveways, this promotes ease of entry and exitfrom the parking stalls and also assures that a driver will not turn hisvehicle around to go back down an up ramp. The fact that there areparking stalls on each side of a driveway which is a single lanedriveway, assures a maximum utilization of the building structure forparking and since the entire building structure is a helical ramp all ofthe ramp surfaces are used for parking and not used merely for travelfrom one floor level to another as in many of the prior art parkinggarages.

The connecting bridges 16 may provide one direction or .two directionsof traffic movement. The first and second helical structures 10 and 12have been shown as being structurally of opposite hand, one spiralingclockwise upwardly and the other spiraling counterclockwise upwardly.With one direction of trafiic flow on a bridge'16, for safety, eitherthe structures may be of opposite hand or the trafiic flow thereon maybe of opposite hand, but not both. As illustrated in FIGURE 1, a vehiclewill spiral clockwise upwardly in the first helical structure 10 andthen cross over on one of the several bridges 16 and spiral clockwisedownwardly in the second helical structure 12. If thissecond helicalstructure 12 were constructed the same as the first helical structure10, namely spiraling clockwise upwardly, then the tr-aflic flow on thissecond helical structure, would be a counterclockwise direction in orderto spiral downwardly.

The bridges 16 may also be made wider to permit twoway traffic flow sothat trafiic may flow from the up helical ramp to the down helical rampor vice versa, in order to best find an available parking stall. In thiscase of two direction trafli-c flow on bridges 16, it is preferred, forsafety purposes, that the structures 10 and 12 be made structurally ofopposite hand, so that the trafiic flow on the bridges from up to downor down to up will not cross each other. In this Way, curbs or bafilesmay be built into the bridges 16 in order to safely direct the trafficflow. It will be noted that in FIGURE 1 in the helical structure 10,upward traffic flow spirals clockwise according to the arrow 11. Incrossing the bridge 16 and going to a downward clockwise spiral,approximately a 180 degree turn to the left is made from the driveway 22onto the bridge 16 and then onto the driveway 23. Accordingly, with aslightly wider bridge 16, it Will be easy to provide a down to uptraflic flow pattern by a 180 degree turn to the left off the driveway23 across the bridge 16 and onto the driveway 22.

While certain illustrative embodiments of the invention have been shown,it is understood that the concepts thereof may be employed in otherembodiments without departing from the spirit and scope of thisinvention. For example, either or both of the helices 10, 12 may beprovided with double lead screw surfaces or helical surfaces. Further,more than three helical structures may be provided with interconnectingbridges and with surfaces which spiral in opposite directions. Stillfurther, any of these embodiments may be provided with undergroundparking ramp portions of all-ramp construction and with the entrancesand exits at the ground, or street level.

What is claimed is:

1. A vehicle parking building comprising a pair of substantiallycircularly helical, all-ramp structures positioned with their axessubstantially vertical,

a helical, single lane driveway radially positioned intermediate eachstructure,

a plurality of vehicle stalls on each side of each drivea plurality ofcolumns arranged in an exterior circle and in an interior circle,

a plurality of exterior edge beams connecting adjacent exterior columns,

a plurality of interior edge beams connecting adjacent interior columns,

a plurality of Wedge-shaped floor beam sections positioned with theirlong dimension bridging the interior and exterior edge beams and formingsaid driveway,

said columns and edge beams providing substantially entirely the supportfor said floor beam sections,

means cooperating with said edge beams to post-tension portions of saidfloor beam sections,

and crossover means connecting at least the upper ends of saidstructures.

2. The combination according to claim 1 wherein said floor beam sectionsare substantially identical,

said post-tensioning means includes at least one radial reinforcing rodand means engaging the outer ends of said reinforcing rod and said edgebeams.

3. The combination according to claim 1 including means establishingonly one-way traflic on said crossover means.

4. The combination according to claim v1 wherein said floor beamsections extend over each of said outer and inner edge beams,

said extensions over said inner edge beams forming a helical pedestrianramp,

and said extensions over said outer edge beams being triangular in shapeforming an end portion of said vehicle stalls.

5. A parking garage comprising a pair of substantially circularlyhelical, all-ramp structures positioned adjacent each other andspiraling in opposite directions, each of said structures including aplurality of exterior columns positioned in a first circle,

a plurality of interior columns positioned in a second circle concentricwith said first circle,

a plurality of exterior edge beams connecting adjacent exterior columns,

a plurality of interior edge beams connecting adjacent interior columns,

a plurality of pre-cast, wedge-shaped floor beams positioned with theirlong dimension bridging the interior and exterior edge beams andextending thereover, said floor beams including at least one T- shapedsection having reinforcing rods therein, certain of said reinforcingrods being prestressed and means on said edge beams for post-tensioningat least one of said rods,

and drive means interconnecting said structures.

6. A vehicle parking garage comprising a pair of helical structures ofall-ramp construction spiraling upwardly in opposite directions, each ofsaid helical structures including a plurality of exterior columnspositioned in a first circle, a plurality of interior columns positionedin a second circle concentric with said first circle, exterior edgebeams connecting said exterior columns and interior edge beamsconnecting said interior columns and tapered floor beams interconnectingsaid exterior and interior edge beams,

said columns and edge beams substantially entirely supporting said floorbeams,

entrance means at one end of one of said helical structures,

exit means at a corresponding end of the other of said structures,

and means interconnecting said structures remote from said entrancemeans and said exit means.

7. The combination according to claim 6 wherein each of said exterioredge beams is L-shaped in cross section with the projecting portion ofthe L directed toward said interior edge beams, each of said interioredge beams being L-shaped in cross section with the projecting portionextending toward said exterior edge beams, said floor beams includingT-sha-ped sections resting upon the projecting portions of said edgebeams.

8. The combination according to claim 6' wherein said floor beamsproject interiorly from said interior edge beams to define a spiralpedestrian ramp and wherein said garage includes railing means aroundsaid pedestrian spiral ramp.

References Cited by the Examiner UNITED STATES PATENTS 1,629,787 5/1927Hackett 52-175 2,689,384 9/1954 Burn 52-175 3,074,209 1/ 1963 Henderson52-283 3,105,999 10/ 1963 Piazolo 52--176 3,136,092 6/1964 Contini 52175FOREIGN PATENTS 233,907 1961 Australia.

564,329 1958 Canada. 1,229,665 1960 France. 1,267,318 1961 France.

8 02,359 1951 Germany.

856,216 1952 Germany.

OTHER REFERENCES Architectural Record Magazine, February 1961, NA 1.A5,pages 146, 147, 148.

FRANK L. ABBOTT, Primary Examiner.

R, A. STENZEL, Assistant Examiner.

1. A VEHICLE PARKING BUILDING COMPRISING A PAIR OF SUBSTANTIALLYCIRCULARLY HELICAL, ALL-RAMP STRUCTURES POSITIONED WITH THEIR AXESSUBSTANTIALLY VERTICAL, A HELICAL, SINGLE LANE DRIVEWAY RADIALLYPOSITIONED INTERMEDIATE EACH STRUCTURE, A PLURALITY OF VEHICLE STALLS ONEACH SIDE OF EACH DRIVEWAY, A PLURALITY OF COLUMNS ARRANGED IN ANEXTERIOR CIRCLE AND IN AN INTERIOR CIRCLE, A PLURALITY OF EXTERIOR EDGEBEAMS CONNECTING ADJACENT EXTERIOR COLUMNS, A PLURALITY OF INTERIOR EDGEBEAMS CONNECTING ADJACENT INTERIOR COLUMNS, A PLURALITY OF WEDGE-SHAPEDFLOOR BEAM SECTIONS POSITIONED WITH THEIR LONG DIMENSION BRIDGING THEINTERIOR AND EXTERIOR EDGE BEAMS AND FORMING SAID DRIVEWAY, SAID COLUMNSAND EDGE BEAMS PROVIDING SUBSTANTIALLY ENTIRELY THE SUPPORT FOR SAIDFLOOR BEAM SECTIONS, MEANS COOPERATING WITH SAID EDGE BEAMS TOPOST-TENSION PORTIONS OF SAID FLOOR BEAM SECTIONS, AND CROSSOVER MEANSCONNECTING AT LEAST THE UPPER ENDS OF SAID STRUCTURES.